4(3H)-oxobenzo-2,1,3-thiadiazine-2,2-dioxides and derivatives thereof

ABSTRACT

Disclosed are novel 4(3H)-oxobenzo-2,1,3-thiadiazine-2,2-dioxides and derivatives and methods employing the same in the control of undesired vegetation.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation-in-part of our copending application Ser. No. 497,583, filed Aug. 15, 1974, now abandoned, which is in turn a continuation-in-part of our earlier application Ser. No. 398,355, filed Sept. 17, 1973, now abandoned.

BACKGROUND

The present invention relates to 4(3H)-oxobenzo-2,1,3-thiadiazine-2,2-dioxides, derivatives thereof and methods for controlling unwanted plants with said compounds.

It is known that 3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide and the salts thereof may be used as herbicide. See U.S. Pat. Nos. 3,708,277 and 3,621,017. Related compounds having pharmacological activities are also known. See, for example, U.S. Pat. Nos. 3,217,001 and 3,041,336. The 3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide compound is known to be useful in selective weed control in corn, sorghum, cereals, rice and turf. However, the action of such compound has not been found to be satisfactory in the control of weeds in the presence of certain desired broadleaf crops, such as cotton, since the compound has been found to exert a significant phytotoxic effect on the desired crop plants at dosage levels required for effective and economical weed control.

It is therefore an object of the instant invention to provide new valuable 4(3H)-oxobenzo-2,1,3-thiadiazine-2,2-dioxides and methods for the use thereof in the control of unwanted plants with negligible effect on the desired crop plants.

SUMMARY OF THE INVENTION

The present invention is directed to novel 4(3H)-oxobenzo-2,1,3-thiadiazine-2,2-dioxide compounds and derivatives thereof corresponding to the formula: ##STR1## wherein: EACH X independently represents loweralkyl, haloloweralkyl, cycloalkyl, aryl, --SCN, --COOR⁵, ##STR2## --YR², --SO₂ R⁵, --SO₂ NR³ R⁴, --CF₃ ; ##STR3## or --YCF₂ C(Z)₃ ; n represents an integer of 1 to 4, inclusive;

m represents an integer of 1 to 2;

R represents loweralkyl, haloloweralkyl, alkenyl, haloalkenyl, alkynyl, haloalkynyl, cycloalkyl, phenyl, loweralkyl phenyl, halophenyl, benzyl, loweralkyl benzyl, halobenzyl, loweralkoxyloweralkyl, diloweralkylaminoloweralkyl; loweralkylthioloweralkyl, or cyanoloweralkyl;

R¹ represents hydrogen, ##STR4## --SO₂ R¹⁰ or --SO₂ NR⁸ R⁹ ; R² and R⁵ each represent alkyl of 1 to 2 carbon atoms;

R³ represents lower alkyl;

R⁴ represents hydrogen or loweralkyl;

R⁶ represents alkyl and haloalkyl each having 1 to 5 carbon atoms, alkenyl and haloalkenyl, each of 2 to 5 carbon atoms, cycloalkyl of 3 to 6 carbon atoms, lower alkoxyloweralkyl and loweralkylthioloweralkyl each of 2 to 6 carbon atoms, alkoxycarbonylalkyl of 4 to 8 carbon atoms, phenyl, loweralkylphenyl or halophenyl;

R⁷ represents alkyl of 1 to 7 carbon atoms, haloalkyl of 1 to 4 carbon atoms, alkenyl and haloalkenyl of 3 to 6 carbon atoms, cycloalkyl of 3 to 6 carbon atoms, phenyl, loweralkylphenyl or halophenyl;

R⁸ represents loweralkyl of 1 to 4 carbon atoms, and cycloalkyl of 3 to 6 carbon atoms; and when taken together with R⁹ and the nitrogen from which each depends, a heterocyclic ring of 4 to 8 carbon atoms;

R⁹ represents R⁸ and alkoxy;

R¹⁰ represents alkyl and haloalkyl, each of 1 to 7 carbon atoms;

each Y, Y' and Y" independently represents a chalcogen group having an atomic number of from 8 to 16 inclusive;

each Z independently represents hydrogen, bromo, chloro or fluoro; and

where R¹ is hydrogen, the salts thereof with organic or inorganic bases.

The method of the present invention of selectively controlling undesired vegetation in the presence of desirable crop plants comprises applying a herbicidally effective amount of the above represented compounds to the area where control is desired.

For the sake of brevity and simplicity, the term "active ingredient(s)" is used hereinafter in this specification to broadly describe the novel 4(3H)-oxobenzo-2,1,3-thiadiazine-2,2-dioxide compounds and derivatives thereof.

DETAILED DESCRIPTION

The active ingredients of the present invention are useful as herbicides, particularly as post-emergent herbicides. Certain of the active ingredients of the present invention have unexpectedly been found to be suitable for controlling undesired vegetation in the presence of desired crops such as for example, cotton, without injuring the same. As used in the present specification and claims, the term "herbicide" means an active ingredient which, when used in a growth controlling amount, controls or modifies the growth of undesired plants. By a "growth controlling amount" is meant an amount of compound which causes a modifying effect upon the growth of plants. Such modifying effects include all deviations from natural development, for example, killing, retardation, defoliation, desiccation, regulation, stunting, tillering, and the like. By "plants" it is meant emerging seedlings and established vegetation, including the roots and above-ground portions.

The term "loweralkyl" is used herein and in the appended claims to designate a straight or branched chain alkyl or haloalkyl radical containing, where not otherwise expressly defined, from 1 to about 6 carbon atoms, such as, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl and the like.

The terms "halo" and "halogen", were employed herein, represent iodine, chlorine, fluorine and bromine. The term "cycloalkyl" is employed to mean radicals containing from 3 to about 8 carbon atoms, such as, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl and the like. The term "aryl" designates phenyl and substituted phenyl such as loweralkylphenyl, e.g., tolyl or xylyl, mono, di or trihalophenyl, and the like. The term "chalcogen" as used herein means those elements of the recognized chalcogen group having an atomic number of 8 to 16, inclusive, i.e., oxygen and sulfur.

The term "alkenyl" unless otherwise defined, as employed in the present specification and claims designates an alkenyl radical containing from about 3 to about 6 carbon atoms, inclusive, such as, for example, propenyl, 2-methyl propenyl, butenyl, hexenyl and the like which optionally may bear one or more halogen substituents. The term "alkenyl" as used herein and in the appended claims designates an alkynyl radical of from about 3 to about 6 carbon atoms, inclusive, such as, for example, propynyl, 2-methyl propynyl, butynyl, pentynyl, hexynyl and the like which optionally may bear one or more halogen substituents.

Those skilled in the art will appreciate the availability and possibility of substitution of the phenyl portion of the molecule corresponding to Formula I with substituents depicted by X_(n) is limited only by the preselected values for X and n and steric considerations involved in placement of substituents about a molecule within a finite space.

If desired, compounds of Formula I, in which R¹ is hydrogen, can be converted into their salts with organic or inorganic bases.

The active ingredients of the present invention are liquids or crystalline solids at room temperature and are soluble in the usual organic solvents and somewhat soluble in water. The active ingredients of the instant invention are generally useful as herbicides. Certain of the active ingredients have been found to be particularly useful as selective post-emergent herbicides in the presence of cotton. In a preferred embodiment of this invention, X is loweralkyl of from one to about 4 carbon atoms. In a further preferred embodiment of the present invention, X is loweralkyl of from one to about four carbon atoms and is substituted in the 8-ring position, n is 1, R is loweralkyl and R¹ is hydrogen, ##STR5## or --SO₂ R¹⁰. In another preferred embodiment, n is 1 and X is loweralkyl of from 1 to about 2 carbon atoms and is substituted in the 8-ring position. In a further embodiment, compounds wherein R is isopropyl and R¹ is hydrogen, ##STR6## or --SO₂ R¹⁰, are preferred.

The active ingredients of the instant invention can be prepared by cyclisng β-sulphamido carboxylic acid derivatives of the general formula: ##STR7## wherein X, n, m, Y, R and R¹ are as previously defined and T is a residue which is easily split off such as, for example, a hydroxy, alkoxy or aryloxy or halo group.

In carrying out the preparation of the compounds of the instant invention are the selected β-sulphamido carboxylic acid can be cyclized to the desired corresponding active ingredient of the instant invention with a condensing agent. Representative examples of condensing agents include, for example, phosphorous oxychloride, thionyl chloride or aqueous or alcoholic alkaline solutions such as, for example, sodium methylate and the like. The reaction can be carried out under ambient atmospheric pressures and be conducted in the presence of inert organic solvents such as, for example, benzene, toluene, xylene, higher ethers, halogenated hydrocarbons and the like. While the reactants can be employed in stoichiometric amounts, an excess amount of condensing agent may also be employed.

The reaction is usually carried out at temperatures of from about 0° to about 150° C., and usually from about 5° to about 110° C. When T is alkoxy the cyclization can be conveniently accomplished in aqueous caustic at about 10° to about 30° C. or in alcoholic alkaline solutions at reflux temperature. The reaction is ordinarily completed in a period of from about 0.25 to 24 hours. The aqueous solution is extracted with an appropriate organic solvent and finally acidified to a pH of about 1.0 to about 3.0 to precipitate the desired product therefrom. Following the substantial completion of the reaction, the reaction mixture is cooled, acidified, and the solvent removed in vacuo. The residue thus obtained is extracted with a suitable solvent, such as, for example, carbon tetrachloride, methylene chloride, chloroform, cyclohexane, or the like, and the extracts combined and cooled to obtain the desired product as a crystalline solid. alternatively, the solvent is removed prior to acidification and the residue obtained dissolved in water, extracted with ether, and the aqueous layer acidified to a pH of about 1.0 to about 3.0 to precipitate the desired product therefrom. If desired, the recovered product can be further purified by recrystallization from a suitable solvent such as hereinbefore mentioned.

The starting materials of formula II can be prepared according to known methods. Procedures for preparing the same as well as literature references to the same are provided in U.S. Pat. No. 3,041,336. Starting materials of Formula II wherein R¹ is hydrogen can, following cyclization as previously set forth, be converted to compounds where R¹ is other than hydrogen by reacting the same with most any of variously substituted halides of carbonic acid, carboxylic acids, sulphonic acids, sulfamic acids, carbamic acids, and other types of selected compounds corresponding to the meaning of R¹ set forth hereinbefore.

Such reactions can be performed in inert organic solvents such as hydrocarbons, halogenated hydrocarbons, alkanones, the dimethyl ether of ethylene glycol or the like and in the presence of alkali carbonates or bicarbonates. Starting materials of Formula II wherein X represents the --Y'CF₂ C(Z)₃ moiety are readily prepared by known or analogous procedures disclosed in the literature. For example, starting materials of formula II, wherein X is --O(S)CF₂ CHCl₂, are readily prepared by sparging 1,1-dichloro-2,2-difluoroethylene into a mixture of sodium methyl hydroxy(thiol)anthranilate in acetone at a temperature of from about 0° C. for a period of about 1 to about 2 hours. Following the completion of the reaction, the solvent is removed by evaporation under reduced pressure and the desired starting material recovered. Those compounds wherein each Z is chloro or bromo are readily prepared by further photochemically halogenating and thus recovering starting material with an appropriate halogenating agent, such as, for example Cl₂ ClBr and the like in known procedures using a solvent such as carbon tetrachloride or a heterogeneous mixture employing water. Those starting materials wherein Z is fluoro are prepared by reacting the starting materials wherein Z is chloro or bromo with a molten antimony fluoro-chloro compound at temperatures of from about 80° to about 120° C. for periods of 1/2 to 2 hours. Other substituents in the 5, 6, 7 and 8 ring positions of the starting materials of Formula II may, depending upon the resistance of such substituent to the preceding reactions, be introduced after cyclization of the same to the corresponding 4(3H)-oxobenzo-2,1,3-thiadiazine-2,2-dioxide compound.

The following examples illustrate the present invention and the manner by which it can be practiced but, as such, should not be construed as limitations upon the overall scope of the same.

EXAMPLE 1

5-Thiocyanoanthranilic acid (8.5 grams; 0.52 mole) was dissolved in 300 milliliters (ml.) of benzene and isopropylsulfamoyl chloride (7 ml.; 0.065 mole) added thereto. The resulting mixture was refluxed for a period of about 2 hours, cooled, and the solvent removed in vacuo. The resulting residue was suspended in 50 ml. of thionyl chloride and the resulting reaction mixture heated at the reflux temperature thereof for a period of about 31/2 hours. Following the reaction period, the reaction mixture was cooled and evaporated in vacuo to obtain an oily residue which was extracted with four 100 ml. portions of carbontetrachloride and subsequently with two 100 ml. portions of methylene chloride. The extracts were combined and cooled to obtain the desired 6-isothiocyanato-3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide product as a crystalline solid having a melting point of 169°-170.5° C. The recovered product was found to have carbon, hydrogen, nitrogen and sulfur contents of 44.70, 3.81, 14.07 and 21.9 percent, respectively, as compared with the theoretical contents of 44.44, 3.70, 14.14 and 21.55 percent, respectively, calculated for the named structure.

EXAMPLE 2

Methyl 3-methyl-2-((((1-methylethyl)amino)-sulfonyl)amino)benzoate (19.9 grams; 0.07 mole) and sodium methylate (7.5 grams; 0.14 mole) were mixed with 200 ml. of methanol and the resulting mixture heated at the reflux temperature thereof for a period of about 4 hours. The reaction mixture was then cooled and the methanol removed in vacuo. The resulting residue was dissolved in 200 ml. of water and the resulting solution extracted with 100 ml. of ether. The aqueous layer was then separated and acidified to a pH of about 2.0 with concentrated hydrochloric acid. The resulting precipitate formed upon acidification was recovered by filtration, dried and recrystallized from cyclohexane. As a result of these operations, the desired 8-methyl-3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide compound was obtained as a crystalline solid having a melting point of 126.5°-127.5° C. and having carbon, hydrogen and nitrogen contents of 51.70, 5.63 and 11.15 percent, respectively, as compared with the theoretical contents of 51.93, 5.51 and 11.02 percent, respectively, calculated for the named structure.

EXAMPLE 3

To 100 ml benzene was added 30 g (.182 mole) of methyl 3-methyl anthranilate and 28.05 ml (0.2 mole) of triethylamine. To the resultant solution was added dropwise 39.4 g of 80% pure isopropylsulfamoyl chloride (0.2 mole) in 200 ml of benzene over a 2 hr period. The mixture was stirred 10 minutes and filtered to afford, upon drying in vacuo, 26.9 g of (C₂ H₅)₃ N.HCl. The solvent was removed from the filtrate in vacuo. The residue was washed once with cyclohexane to afford upon decantation and drying the residue in vacuo 56.6 g of gummy black solid identified by NMR as mainly desired intermediate methyl 3-methyl-2-((isopropyl)amino)sulfonyl)amino)benzamide.

The crude intermediate 55.6 g) was dissolved in 550 ml of 5% aqueous NaOH and the dark solution stirred 1 hour. The solution was titrated to pH=9 with concentrated HCl and extracted with three 100 ml-portions of CH₂ Cl₂.

The aqueous layer was acidified to pH=1, stirred for 0.5 hour in an ice bath causing solidification of a precipitate, which was filtered off, and dried at 50° C in vacuo to afford 30.3 g of crude product containing ca 10% of 3-methyl anthranilic acid or its hydrochloride salt.

The tan solid was recrystallized from 300 ml of CCl₄ to afford 1.1 g of dark brown insoluble solid at reflux. The filtrate gave 25.0 g of 8-methyl-3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide as tan crystals, m.p. 126°-129° C.

Other active ingredients of the instant invention are similarly prepared by employing procedures analogous to those set forth in Examples 1 through 3 above and the foregoing teachings of the specification by cyclizing a selected β-sulphamido carboxylic acid with a condensing agent. In addition the 1-substituted analogs such as those listed in the following table are prepared by causing the sodium or potassium salts of the thiadiazines in which R¹ is hydrogen to react with the appropriate halide in an invert solvent. Such other products corresponding to Formula I include the following:

                                      TABLE I                                      __________________________________________________________________________     Cmpd.            Ring                        Melting                           No. X            Position                                                                            R        R.sup.1    m  Temperature, °             __________________________________________________________________________                                                  C                                  4  CH.sub.3     7    i-C.sub.3 H.sub.7                                                                       H          2  159-161                            5  OCH.sub.3    8    i-C.sub.3 H.sub.7                                                                       H          2  113-114                            6  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                        ##STR8##  2  103-104.5                          7  CF.sub.3     8    i-C.sub.3 H.sub.7                                                                       H          2  88-91                              8  SO.sub.2 CH.sub.3                                                                           8    i-C.sub.3 H.sub.7                                                                       H          2  139.5-140.5                        9  CH.sub.3     6    i-C.sub.3 H.sub.7                                                                       H          2  166-167                           10  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                        ##STR9##  2  (R.sub.f.sup.25°                                                        1.5537)                           11  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                        ##STR10## 2  82.84                             12  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                       SO.sub.2 N(CH.sub.3).sub.2                                                                2  140-142                           13  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                        ##STR11## 2  110-112                           14  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                        ##STR12## 2  122-124                           15  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                        ##STR13## 2  62.5-64                           16  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                       SO.sub.2 C.sub.3 H.sub.7                                                                  2  96-97                             17  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                        ##STR14## 2  116-118                           18  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                       SO.sub.2 CH.sub.3                                                                         2  168-170                           19  C.sub.2 H.sub.5                                                                             8    i-C.sub.3 H.sub.7                                                                       H          2  59-62                             20  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                       H          2  126-129                           21  SCH.sub.3    8    i-C.sub.3 H.sub.7                                                                       H          2  93.5-94                           22  SCN          6    i-C.sub.3 H.sub.7                                                                       H          2  169-170.5                         23  CH.sub.3     8    n-C.sub.3 H.sub.7                                                                       H          2  96-97                             24  CH.sub.3     8    C.sub.2 H.sub.5                                                                         H          2  91-93                             25  CH.sub.3     8    CH.sub.3 H          2  109-110                           26  CH.sub.3     8    n-C.sub.4 H.sub.9                                                                       H          2  101-103                           27  CH.sub.3     8    i-C.sub.4 H.sub.9                                                                       H          2  108-110                           28  di-CH.sub.3  7,8  i-C.sub.3 H.sub.7                                                                       H          2  154-157                           29  CH.sub.3     8                                                                                    ##STR15##                                                                              H          2  173.5-174.5                       30  OCH.sub.3    6    i-C.sub.3 H.sub.7                                                                       H          2  147.5-149                         31  CF.sub.3     7    i-C.sub.3 H.sub.7                                                                       H          2  212-214                           32  di-CH.sub.3  6,8  i-C.sub.3 H.sub.7                                                                       H          2  141-143                           33  di-CH.sub.3  5,8  i-C.sub.3 H.sub.7                                                                       H          2  170-171                           34  i-C.sub.3 H.sub.7                                                                           8    i-C.sub.3 H.sub.7                                                                       H          2  121-123                           35  CH.sub.3     5    i-C.sub.3 H.sub.7                                                                       H          2  131-135                           36  OCH.sub.3    8    s-C.sub.4 H.sub.9                                                                       H          2  100.5-102.5                       37  OCH.sub.3    8    n-C.sub.3 H.sub.7                                                                       H          2  106-109                           38  CH.sub.3     8    t-C.sub.4 H.sub.9                                                                       H          2  115-116                           39  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                        ##STR16## 2  82- 84                            40  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                        ##STR17## 2  41.5-44                           41  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                       SO.sub.2n-C.sub.4 H.sub.9                                                                 2  79.5-81                           42  CH.sub.3     8    i-C.sub.3 H.sub.7                                                                        ##STR18## 2  79-81                             43  CH.sub.3     8    s-C.sub.4 H.sub.9                                                                       H          2  109-112                           44  CH.sub.3     5,8  CH.sub.2CH.sub.2 Cl                                                                     H          2                                    45                                                                             n-C.sub.3 H.sub.7                                                                  8            C.sub.2 H.sub.4 Cl                                                                  H        2                                               46  C.sub.6 H.sub.11 F.sub.2                                                                    5                                                             i-C.sub.3 H.sub.7                                                                  H            2                                                             47  phenyl       8                                                             i-C.sub.3 H.sub.7                                                                  H            2                                                             48  p-tolyl      7    C.sub.2 H.sub.5                                                                         H          1                                    49  CH.sub.3     5,8  C.sub.5 H.sub.10 Cl                                                                     H          1                                    50  OCH.sub.3    8                                                             i-C.sub.3 H.sub.7                                                                  H            1                                                             51  SC.sub.6 H.sub.11                                                                           6    CH.sub.3 H          2                                    52  6-SCN, 8-CH.sub.3                                                                           6,8  CH.sub.2 CHCH.sub.2                                                                     H          2                                    53  6-t-C.sub.4 H.sub.9                                                                         6                                                                                    ##STR19##                                                                              H          2                                    54  COOCH.sub.3  7                                                                                    ##STR20##                                                                              SO.sub.2 CH.sub.3                                                                         2                                    55  CF.sub.3     6                                                             i-C.sub.3 H.sub.7                                                                  CO.sub.2n-C.sub.4 H.sub.9                                                                   2                                                             56  CF.sub.3     6                                                             n-C.sub.16 H.sub.13                                                                H            2                                                             57  5-CH.sub.2 Cl, 7-SC.sub.2 H.sub.5                                                           5,7  CH.sub.2 CH.sub.3                                                                       H          2                                    58  5-CH.sub.3,8-OC.sub.3 H.sub.7                                                               5,8                                                           i-C.sub.3 H.sub.7                                                                  SO.sub.2 CH.sub.3                                                                           2                                                             59  5-NHC.sub.6 H.sub.11, 8-CH.sub.3                                                            5,8  CH.sub.2 CHCHCl                                                                         H          2                                    60                                                                                  ##STR21##   6    CH.sub.3 H          2                                    61  6-cyclohexyl;                                                                               6,8  CH.sub.2 CH.sub.2 CH.sub.3                                                              H          2                                        8-CH.sub.2 F                                                               62  CH.sub.3     5,6,7                                                         i-C.sub.3 H.sub.7                                                                  H            2                                                             63  SO.sub.2 C.sub.6 H.sub.11                                                                   6    cyclohexyl                                                                              H          2                                    64  CF.sub.3     5,7, CH.sub.2 CH.sub.2 CH.sub.3                                                              H          2                                    65  CF.sub.3     5,7                                                           cyclopropyl                                                                        H            1                                                             66  6-SO.sub.2 N(C.sub.2 H.sub.5).sub.2, 8-CH.sub.3                                             6,8                                                           i-C.sub.3 H.sub.7                                                                  H            2                                                             67  6-SCN, 8-OCH.sub.3                                                                          6,8  C.sub.2 H.sub.5                                                                         CO.sub.2 CH.sub.3                                                                         2                                    68  CH.sub.2 CHF.sub.2                                                                          6    i-C.sub.3 h.sub.7                                                                       SO.sub.2n-C.sub.3 H.sub.7                                                                 2                                    69  OCF.sub.2 CHCl.sub.2                                                                        8                                                             i-C.sub.3 H.sub.7                                                                  H            1                                                             70  SCF.sub.2 CCl.sub.3                                                                         6    i-C.sub.3 H.sub.7                                                                       H          2                                    71  5-OCF.sub.2 CH.sub.2 F, 8-CH.sub.3                                                          5,8  CH.sub.2 CH.sub.2 CH.sub.3                                                              H          2                                    72  8-SCF.sub.2 CF.sub.3                                                                        8    CH.sub.2 CH.sub.3                                                                       H          1                                    73  CH.sub.3     8                                                                                    ##STR22##                                                                              H          2                                    74  CH.sub.3     8                                                                                    ##STR23##                                                                              H          2                                    75  5-CF.sub.3   5                                                                                    ##STR24##                                                                              COCH.sub.3 2                                    76  6-OCF.sub.2 CHCl.sub.2                                                                      6                                                                                    ##STR25##                                                                              SO.sub.2 CH.sub.3                                                                         2                                    77  OCH.sub.3    8    i-C.sub.3 H.sub.7                                                                       H          2                                    78  CH.sub.3     8    cyclohexyl                                                                              H          2                                    79  CH.sub.3     8    sec. butyl                                                                              H          2                                    80  CH.sub.2 CH.sub.3                                                                           8    i-C.sub.3 H.sub.7                                                                       H          2                                    81  OCH.sub.3    8    C.sub.2 H.sub.5                                                                         H          2                                    82  N(CH.sub.3).sub.2                                                                           8    i-C.sub.3 H.sub.7                                                                       H          2                                    83  OCH.sub.3    5    i-C.sub.3 H.sub.7                                                                       H          2                                    84  CH.sub.3     8    sec. butyl                                                                              H          2                                    85  CH.sub.3     8    phenyl   H          2                                    86  CH.sub.3     8    tolyl    H          2                                    87  CH.sub.3     8    CH.sub.2 SCH.sub.3                                                                      H          2                                    88  CH.sub.3     8    CH.sub.2 N(C.sub.2 H.sub.5).sub.2                                                       H          2                                    89  CH.sub.3     8                                                                                    ##STR26##                                                                              H          2                                    90  CH.sub.3     8                                                                                    ##STR27##                                                                              H          2                                    __________________________________________________________________________

the compounds of the present invention have been found to be suitable for use in the post-emergent control of weeds or other unwanted vegetation. Unexpectedly, certain of the active ingredients of the present invention have been found to be active against undesired vegetation in the presence of desired cotton plants while producing only a negligible effect on the cotton plants. For such uses, unmodified active ingredients of the present invention can be employed. However, the present invention embraces the use of active ingredients with a material known in the art as an adjuvant in solid or liquid form. Thus, for example, an active ingredient can be dispersed on a finely divided solid and employed therein as a dust. Also, the active ingredients, or a solid composition comprising the active ingredients, can be dispersed in water, typically with the aid of a wetting agent, and the resulting aqueous suspension employed as a spray. In other procedures, the active ingredient can be employed as a constituent of organic liquid compositions, oil-in-water and water-in-oil emulsions, or water dispersions, with or without the addition of wetting, dispersing, or emulsifying agents.

Suitable adjuvants of the foregoing type are well known to those skilled in the art. The methods of applying the solid or liquid herbicidal formulations similarly are well know to the skilled artisan.

As organic solvents there can be employed hydrocarbons, e.g. benzene, toluene, xylene, kerosene, diesel fuel, fuel oil, and petroleum naphtha, ketones such as acetone, methyl ethyl ketone and cyclohexanone, chlorinated hydrocarbons such as carbon tetrachloride, chloroform, trichloroethylene, and perchloroethylene, esters such as ethyl acetate, amyl acetate and butyl acetate, ethers, e.g., ethylene glycol momomethyl ether and diethylene glycol monomethyl ether, alcohols, e.g., methanol, ethanol, isopropanol, amyl alcohol, ethylene glycol, propylene glycol, butyl Carbitol acetate and glycerine. Mixtures of water and organic solvents, either as solutions or emulsions, can be employed.

The active ingredients can also be applied as aerosols, e.g., by dispersing them in air by means of a compressed gas such as dichlorodifluoromethane or trichlorofluoromethane and other Freons and Genetrons, for example.

The active ingredients of the present invention can also be applied with adjuvants or carriers such as talc, pyrophyllite, synthetic fine silica, attapulgus clay, kieselguhr, chalk, diatomaceous earth, lime, calcium carbonate, bentonite, fuller's earth, cottonseed hulls, wheat flour, soybean flour, pumice, tripoli, wood flour, walnut shell flour, redwood flour and lignin.

As stated, it is frequently desirable to incorporate a surface active agent in the compositions of the present invention. Such surface active or wetting agents are advantageously employed in both the solid and liquid compositions. The surface active agent can be anionic, cationic or non-ionic in character.

Typical classes of surface active agents include alkyl sulfonate salts, alkylaryl sulfonate salts, alkylaryl polyether alcohols, fatty acid esters of polyhydric alcohols and the alkylene oxide addition products of such esters, and addition products of long chain mercaptans and alkylene oxides. Typical examples of such surface active agents include the sodium alkylbenzene sulfonates having 10 to 18 carbon atoms in the alkyl group, alkylphenol ethylene oxide condensation products, e.g., p-isooctylphenol condensed with 10 ethylene oxide units, soaps, e.g., sodium stearate and potassium oleate, sodium salt of propylnaphthalene sulfonic acid, di(2-ethylhexyl)ester of sodium sulfosuccinic acid, sodium lauryl sulfate, sodium decane sulfonate, sodium salt of the sulfonated monoglyceride of coconut fatty acids, sorbitan sesquioleate, lauryl trimethyl ammonium chloride, octadecyl trimethyl ammonium chloride, polyethylene glycol lauryl ether, polyethylene glycol esters of fatty acids and rosin acids, e.g., Ethofat 7 and 13, sodium N-methyl-N-oleyl taurate, Turkey Red Oil, sodium dibutyl naphthalene sulfonate, sodium lignin sulfonate, polyethylene glycol stearate, sodium dodecylbenzene sulfonate, tertiary dodecyl polyethylene glycol thioether (nonionic 218), long chain ethylene oxide-propylene oxide condensation products, e.g., Pluronic 61 (molecular weight 1000), polyethylene glycol ester of tall oil acids, sodium octyl phenoxyethoxyethyl sulfate, tris(polyoxyethylene)sorbitan monostearate (Tween 60), and sodium dihexyl sulfosuccinate.

The concentration of the active ingredients in liquid compositions generally is from about 5 to about 95 percent by weight or more. Concentrations of from about 5 to about 50 weight percent are often employed. In dusts or dry formulations, the concentration of the active ingredient can be from about 0.1 to about 95 weight percent or more; concentrations of from about 1 to about 50 weight percent are often conveniently employed. In compositions to be employed as concentrates, the active ingredient can be present in a concentration of from about 5 to about 98 weight percent. The active ingredient compositions can also contain other compatible additaments, for example, fertilizers, phytotoxicants, plant growth regulants, pesticides and the like.

The active ingredients are most usefully brought into commerce in the form of (1) a wettable powder in which one or more of the active ingredients in finely divided form are blended with one of the wetting agents or surfactants above listed with or without combination, also with a finely divided absorptive clay or other absorptive inert adjuvant or carrier as listed above; (2) a flowable concentrate which corresponds largely to a "pre-wet" wettable powder composition having as high as 50 percent solids content and containing water and/or other appropriate liquid as well understood in the formulation art and (3) an emulsifiable concentrate in which one or more of the active ingredients are dissolved in an organic solvent, such as one of those listed, in admixture with a wetting, dispersing, or emulsifying agent, such as those described above, whereby the concentrate will readily become an emulsion on dilution with water.

In general treating operations for the modification and control of vegetative growth, plants are contacted with sufficient amounts of a composition containing one or more active ingredients to provide a dosage rate of from about 0.1 to about 30 or more pounds of active ingredient per acre, preferably about 0.1 to about 10 pounds per acre. In selective post-emergent operations in the presence of desired cotton plants, the active ingredients are applied at a rate of from about 0.25 to about 4.0 pounds per acre. It is to be understood, however, that all of the active ingredients claimed and compositions containing the same may not be equally effective at similar concentrations against the same plant species.

The present compounds are particularly useful in selectively controlling undesired vegetative growth in the presence of soybean plants in post emergent operations in which the active ingredients are applied at a rate of from about 0.25 to about 4 pounds per acre, and preferably at a rate of from about 0.25 to 2 pounds per acre.

So as to illustrate clearly the phytotoxic properties of the active ingredients claimed herein, a group of controlled greenhouse experiments is described below.

Various species of plants (A-J below) were planted in beds of good agricultural soil in a greenhouse. After the plants had emerged and grown to a height of about 2-6 inches, a portion of the plants was sprayed with an aqueous mixture made by mixing the selected active ingredient and emulsifier or dispersant with water, employing sufficient amounts of the treating compositions to provide application rates of 0.5, 1.0 and 2.0 pounds per acre. Other portions of the plants were left untreated to serve as controls.

After a period of 2 weeks the effect of the 8-methyl-3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide test ingredient (Compound 2 (a-c)) and the comparative test ingredient, 3-(1-methylethyl)-1H-2,1,3-benzothiadiazine-4(3H)-one-2,2-dioxide (Compound 1 (a-c)), on the plants was evaluated and the data set forth in the following Table II. The data show the selective superiority of the 8-methyl substituted derivative over the corresponding unsubstituted derivative.

                                      TABLE II                                     __________________________________________________________________________     Percent Post-Emergent Control of Plants                                               Rate                                                                    Cmpd. No.                                                                             Lbs/Acre                                                                            A  B  C  D  E  F  G  H  I  J                                       __________________________________________________________________________     1a.    2.0  100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                      b.    1.0  100                                                                               100                                                                               100                                                                                75                                                                               100                                                                                85                                                                               100                                                                                80                                                                               100                                                                                65                                      c.    0.5  100                                                                               100                                                                               100                                                                                55                                                                               100                                                                                60                                                                               100                                                                                35                                                                                70                                                                                30                                     2a.    2.0  100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                               100                                                                                25                                      b.    1.0  100                                                                               100                                                                               100                                                                               100                                                                               100                                                                                75                                                                               100                                                                               100                                                                               100                                                                                10                                      c.    0.5  100                                                                               100                                                                               100                                                                                80                                                                               100                                                                               -- 100                                                                               100                                                                               100                                                                                5                                      __________________________________________________________________________      A = Cocklebur, B = Prickly Sida, C = Wild Mustard, D = Field Bindweed, E       Jimson Weed, F = Pigweed, G = Lambsquarter, H = Coffeeweed, I = Velvet         Leaf, and J =  Cotton                                                    

In additional operations employing the above procedures, 1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide was found to give 0% control of the weed species wildoats, foxtail, barnyard grass, crabgrass, pigweed, bindweed and velvet leaf even at a high dosage rate of eight pounds per acre. In other similar operations, 6-isothiocyanato-3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide gave 100% control of velvet leaf with no effect on cotton plants.

In further comparative operations employing the above described procedures and test ingredient dosage rates of 1, 1/2 and 1/4 pounds per acre, respectively, it was found that 3,8-dimethyl-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide (Compound A) and 3-ethyl-8-methyl-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide (Compound B) were selectively active in completely controlling velvet leaf at low dosage rates of 1/4 and 1/4 pounds per acre, respectively, with negligible effect on cotton whereas 3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide (Compound C) was significantly toxic to cotton and also failed to give good control of velvet leaf at such low dosage rates. The results of such tests are set forth below in Table III.

                  TABLE III                                                        ______________________________________                                         Cmpd.     Dosage Rate % Control                                                No.       lbs/Acre    Velvet Leaf  Cotton                                      ______________________________________                                         A         1.0         100%         45%                                                   0.5         100%         15%                                                   0.25        100%          0%                                         B         1.0         100          25                                                    0.5         100           0                                                    0.25        100           0                                          C         1.0         100          65                                                    0.5          70          30                                                    0.25         45          10                                          ______________________________________                                    

In similar additional operations, 8-methyl-3-propyl-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide gave 100, 95 and 90% control of bindweed and 20, 15 and 0% control of cotton at dosage rates of 1, 1/2 and 1/4 pounds per acre, respectively. By comparison, the 3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide compound gave 75, 55 and 35 percent control of bindweed and 65, 30 and 10% control of cotton at such respective dosage rates, thus indicating the superior activity and safety of the 8-methyl-3-propyl-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide compound at low dosage rates.

In similar operations employing the foregoing procedures, each of the 8-ethyl-3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide and 3-cyclohexyl-8-methyl-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide test ingredients gave substantially complete control of pigweed and velvet leaf at an application rate of about 10 pounds per acre while the 3-(1-methylethyl)-7-(trifluoromethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide test ingredient was found to give substantially complete control of the growth of pigweed and nutsedge at such application rate.

In other representative operations employing procedures as outlined above, each of the 8-methyl-3-(1-methylethyl)-1-(phenylsulfonyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide and 7,8-dimethyl-3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide test ingredients was found to give substantially complete control of the growth of velvet leaf at an application rate of about 10 pounds per acre. No adverse growth effects to cotton plants were observed with either test ingredient at such application rate.

In still other such representative operations, the respective 8-methoxy-3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide and 8-methyl-3-(1-methylpropyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide test ingredients were found to give substantially complete control of velvet leaf and pigweed, respectively, at an application rate of about 0.3 pound per acre. No adverse growth effects on cotton plants were observed at such application rate.

The above and other certain active ingredients of the present invention are also found to exhibit selective herbicidal activities at various application rates. 

What is claimed is:
 1. A compound corresponding to the formula: ##STR28## wherein: each X independently represents loweralkyl, haloloweralkyl, cycloalkyl having from 3 to about 8 carbon atoms, phenyl, loweralkylphenyl, halophenyl, --SCN, --COOR⁵, ##STR29## --YR², --SO₂ R⁵, --SO₂ NR³ R⁴, --CF₃, ##STR30## or --Y'CF₂ C(Z)₃ ; n represents an integer of 1 to 4, inclusive;m represents an integer of 1 or 2; R represents loweralkyl, haloloweralkyl; alkenyl, haloalkenyl, alkynyl and haloalkynyl, each of about 3 to about 6 carbon atoms; cycloalkyl of 3 to about 8 carbon atoms; phenyl, loweralkylphenyl, halophenyl, benzyl, loweralkylbenzyl, halobenzyl, loweralkoxyloweralkyl, diloweralkylaminoloweralkyl; loweralkylthioloweralkyl, or cyanoloweralkyl; R¹ represents hydrogen, ##STR31## --SO₂ R¹⁰ or --SO₂ NR⁸ R⁹ ; R² and R⁵ each represent alkyl of 1 to 2 carbon atoms; R³ represents loweralkyl; R⁴ represents hydrogen or loweralkyl; R⁶ represents loweralkyl and hololoweralkyl each having from 1 to 5 carbon atoms, alkenyl and haloalkenyl of 2 to 5 carbon atoms, cycloalkyl of 3 to 6 carbon atoms, loweralkoxyloweralkyl and loweralkylthioloweralkyl, each of 2 to 6 carbon atoms, alkoxycarbonylalkyl of 4 to 8 carbon atoms, phenyl, loweralkylphenyl or halophenyl; R⁷ represents alkyl of 1 to 7 carbon atoms, haloalkyl of 1 to 4 carbon atoms, alkenyl and haloalkenyl of 3 to 6 carbon atoms, cycloalkyl of 3 to 6 carbon atoms, phenyl, loweralkylphenyl or halophenyl; R⁸ represents loweralkyl of 1 to 4 carbon atoms and cycloalkyl of 3 to 6 carbon atoms; R⁹ represents R⁸ and alkoxy, and when taken together with R⁸ and the nitrogen from which each depends, a heterocyclic ring of 4 to 8 carbon atoms; R¹⁰ represents alkyl and haloalkyl, each of 1 to 7 carbon atoms; each Y, Y' and Y" independently represents a chalcogen group having an atomic number of from 8 to 16 inclusive; each Z independently represents hydrogen, bromo, chloro or fluoro; and where R¹ is hydrogen, the salts thereof with organic or inorganic bases.
 2. The compound of claim 1 wherein m is
 2. 3. The compound of claim 2 wherein R is loweralkyl.
 4. The compound of claim 2 wherein R is loweralkyl and R¹ is hydrogen.
 5. The compound of claim 2 wherein R is loweralkyl and R¹ is ##STR32##
 6. The compound of claim 2 wherein R is loweralkyl and R¹ is --COY"R⁷.
 7. The compound of claim 2 wherein R is loweralkyl and R¹ is --SO₂ R¹⁰.
 8. The compound of claim 1 wherein R is 1-methylethyl.
 9. The compound of claim 3 wherein X is loweralkyl of from 1 to about 4 carbon atoms.
 10. The compound of claim 9 wherein n is
 1. 11. The compound of claim 3 wherein X is loweralkyl of from 1 to about 2 carbon atoms, n is 1, and R¹ is selected from hydrogen ##STR33## and --SO₂ R¹⁰.
 12. The compound of claim 11 in which X is in one of the 6, 7 or 8 ring positions.
 13. The compound of claim 2 which is 8-methyl-3-(n-propyl)-1H-2,1,3-benzothiadiazin-4-(3H)-one-2,2-dioxide.
 14. The compound of claim 2 which is 8-methyl-3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide.
 15. The compound of claim 2 which is 8-methyl-3-(sec. butyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide.
 16. The compound of claim 2 which is 3,4-dihydro-8-methyl-3-(1-methylethyl)-4-oxo-1H-2,1,3-benzothiadiazine-1-carboxylic acid, methyl ester, 2,2-dioxide.
 17. The compound of claim 2 which is 3,4-dihydro-8-methyl-3-(1-methylethyl)-4-oxo-1H-2,1,3-benzothiadiazine-1-carboxylic acid, propyl ester, 2,2-dioxide.
 18. The compound of claim 2 which is 8-methyl-3-(1-methylethyl)-1-acetyl-11H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide.
 19. The compound of claim 2 which is 8-methyl-3-(1-methylethyl)-1-(1-oxobutyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide.
 20. The compound of claim 2 which is 3,4-dihydro-8-methyl-3-(1-methylethyl)-4-oxo-1H-2,1,3-benzothiadiazine-carboxylic acid, butyl ester, 2,2-dioxide.
 21. The compound of claim 2 which is 8-methoxy-3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide
 22. The compound of claim 2 which is 3,4-dihydro-8-methyl-3-(1-methylethyl)-4-oxo-1H-2,1,3-benzothiadiazine-1-carbothioic acid, S-methyl ester, 2,2-dioxide.
 23. The compound of claim 2 which is 3,4-dihydro-8-methyl-3-(1-methylethyl)-4-oxo-1H-2,1,3-benzothiadiazine-1-carbothioic acid, S-propyl ester, 2,2-dioxide.
 24. The compound of claim 2 which is 8-methyl-3-(1-methylethyl)-1-methylsulfonyl-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide.
 25. The compound of claim 2 which is 8-methyl-3-(1-methylethyl)-1-propylsulfonyl-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide.
 26. The compound of claim 2 which is 8-methyl-3-(1-methylethyl)-1-butylsulfonyl-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide.
 27. The compound of claim 1 which is 3-(1-methylethyl)-(8-trifluoromethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide. 